The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 30, 2002
Filed:
Oct. 31, 2000
Yusaku Nozawa, Ibaraki-ken, JP;
Mitsuhisa Tougasaki, Ibaraki-ken, JP;
Yoshizumi Nishimura, Tsuchiura, JP;
Kinya Takahashi, Tsuchiura, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
A hydraulic line slit formed in a valve body of a flow distribution valve - , a control chamber , and a hydraulic line - are connected to a signal transmitting hydraulic line . A lap portion is formed in the hydraulic line slit , the lap portion having a check valve function with a lap amount X when the valve body is in a cutoff position. A 2-position, 3-way valve is disposed in the hydraulic line - . The valve connects the control chamber of the flow distribution valve - to only the signal transmitting hydraulic line when an external signal F is not applied, and to both the signal transmitting hydraulic line and a lower-pressure detecting hydraulic line , which is connected an outlet passage of a flow distribution valve - on the side of a hydraulic actuator - , when the external signal F is applied. With such an arrangement, during a combined operation including driving of an inertial body, a pressure on the lower load pressure side can be detected as a signal pressure without cutting off a load-pressure detecting hydraulic line on the higher load pressure side. Further, a portion for detecting a load pressure is simplified and the flow distributing function is not impaired.